A CMOS multichannel 10-Gb/s transceiver

We describe a CMOS multichannel transceiver that transmits and receives 10 Gb/s per channel over balanced copper media. The transceiver consists of two identical 10-Gb/s modules. Each module operates off a single 1.2-V supply and has a single 5-GHz phase-locked loop to supply a reference clock to two transmitter (Tx) channels and two receiver (Rx) channels. To track the input-signal phase, the Rx channel has a clock recovery unit (CRU), which uses a phase-interpolator-based timing generator and digital loop filter. The CRU can adjust the recovered clock phase with a resolution of 1.56 ps. Two sets of two-channel transceiver units were fabricated in 0.11-/spl mu/m CMOS on a single test chip. The transceiver unit size was 1.6 mm /spl times/ 2.6 mm. The Rx sensitivity was 120-mVp-p differential with a 70-ps phase margin for a common-mode voltage ranging from 0.6 to 1.0 V. The evaluated jitter tolerance curve met the OC-192 specification.     

A new lateral MOS-gated thyristor with controlling base-current

A new lateral MOS-gated thyristor, called the Base-Current-Controlled Thyristor, is described. This device is designed so that most holes at the on-stage reach the P base through the floating P⁺ region adjacent to the P base and the on-state MOSFET. At the turn-off stage, the interruption of the hole current to the P base due to switching off the above MOSFET occurs simultaneously with the conventional turn-off operation. The concept of this device is verified experimentally by using the fabricated lateral device with the external MOSFET. This device exhibits a better trade-off relation between the on-state voltage and the turn-off time compared uith the conventional MOS-gated thyristor     

Neural mechanism of pupillary dilation elicited by electro-acupuncture stimulation in anesthetized rats

The neural mechanisms to reflex dilation elicited by electro-acupuncture stimulation were investigated in anesthetized rats. Two needles, with 160 microns diameter and about 5 mm apart, were inserted into the skin and underlying muscle of a hindpaw. Repetitive 20 Hz, 0.5 ms electrical pulses at various intensities were used for stimulation for 30s. The pupil size was magnified about 44 times via a microscope and was continuously recorded on a videotape. Electro-acupuncture stimulation at more than 0.5 up to 6 mA induced stimulus intensity-dependent pupil dilation. These responses were abolished by the severance of the sciatic and saphenous nerve of the stimulated hindlimb. Compound action potentials were recorded from the distal cut end of the tibial of a saphenous nerve following electro-acupuncture stimulation of the hindpaw. The mean threshold of the compound action potentials of the myelinated fibers in saphenous nerves was 0.18 mA, while that of unmyelinated fibers was 3.0 mA. The mean threshold of the compound action potentials of the myelinated fibers in the tibial nerve was 0.20 mA of unmyelinated fibers was 3.3 mA. Severance of bilateral trunks did not affect the response, while severance of the third cranial nerves abolished the responses. In conclusion, electro-acupuncture stimulation applied to the hindpaws of the anesthetized rats induced excitation of myelinated or of both myelinated and unmyelinated afferent fibers of the tibial and saphenous nerve, and involved a reflex response of pupil dilation through the third cranial parasympathetic efferent nerve.     

Highly reliable 200 mW AlGaAs laser diode with fundamental transverse mode

A highly reliable 200 mW AlGaAs laser diode with a fundamental transverse mode has been developed, by optimising its structure with a 0.8 mu m thick p-cladding layer, a 1200 mu m long cavity length, and a front facet coating with a low reflectivity of 2%. The maximum output power was 500 mW, and stable fundamental transverse mode operation was obtained up to 350 mW. Stable operation under 200 mW and 50 degrees C was confirmed for more than 1200 h. Optical feedback noise was below 3*10/sup -14/ Hz/sup -1/.<>     

Theoretical model for flash generation

Reduction of flash generated in a gas vent is of great concern for manufacturers of electronic parts. The present study proposes a theoretical model for flash generation through consideration of flow characteristics in a gas vent. The model predicts the factors controlling flash, i.e., material parameters such as zero‐shear viscosity, crystallization temperature, thermal conductivity, and heat capacity, and process parameters such as injection and mold wall temperatures, packing pressure, and the clearance of a gas vent. On the other hand, we measure the amount of flash generated in the molding of poly(phenylene sulfide) (PPS) composites containing glass fiber and spherical fillers (CaCO₃ or Al₂O₃). Flash reduces with decreasing size of spherical fillers. These experimental data are successfully interpreted using the flash model. Polym. Eng. Sci., 45:198–206, 2005. © 2005 Society of Plastics Engineers     

Operation of superconducting fault current limiter using vacuum interrupter driven by electromagnetic repulsion force for commutating switch

Using conventional high‐temperature superconducting wire, a model superconducting fault current limiter (SFCL) is made and tested. Solenoid coil using Bi2223 silver sheath wire is so made that inductance is as small as possible and a vacuum interrupter is connected in series to it. A conventional reactor coil is connected in parallel. When the fault current flows in this equipment, superconducting wire is quenched and current is transferred into the parallel coil because of voltage drop of superconducting wire. This large current in parallel coil actuates magnetic repulsion mechanism of vacuum interrupter. Due to opening of vacuum interrupter, the current in superconducting wire is broken. By using this equipment, current flow time in superconducting wire can be easily minimized. On the other hand, the fault current is also easily limited by large reactance of parallel coil. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 164(1): 52–61, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20315     

Characterization and electrochemical properties of CF4 plasma-treated boron-doped diamond surfaces

The effect of CF₄ plasma etching on diamond surfaces, with respect to treatment time, was investigated using scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and electrochemical measurements. SEM observations and Raman spectra indicated an increase in surface roughening on a scale of 10–20 nm, and an increase in crystal defect density was apparent with treatment time in the range of 10 s to 30 min. In contrast, alteration of the diamond surface terminations from oxygen to fluorine was found to be rather rapid, with saturation of the F/C atomic ratio estimated from XPS analysis after treatment durations of 1 min and more. The redox kinetics of Fe(CN)₆^3−/4− was also found to be significantly modified after 10 s of CF₄ plasma treatment. This behavior shows that C–F terminations predominantly affect the redox kinetics compared to the effect on the surface roughness and crystal defects. The double-layer capacitance (C_dl) of the electrolyte/CF₄ plasma-treated boron-doped diamond interface was found to show a minimum value at 1 min of treatment. These results indicate that a short-duration CF₄ plasma treatment is effective for the fabrication of fluorine-terminated diamond surfaces without undesirable surface damage.     

Expression studies of delta-globin gene alleles associated with reduced hemoglobin A2 levels in Greek Cypriots

We previously identified five delta-globin gene alleles associated with reduced hemoglobin (Hb) A2 (Trifillis, P., Ioannou, P., Schwartz, E., and Surrey, S. (1991) Blood 78, 3298-3305). We have now evaluated functional consequences of the changes after expression in COS-1 cells to monitor effects on RNA splicing. In addition, variant Hb A2 tetramers were expressed in yeast to assess effects of amino acid changes on oxygen binding and stability to heat and mechanical agitation. The G --> T change at codon 27 and the A --> G change in IVS-2 both affect RNA splicing, whereas the C --> T change at codon 97 and the AT deletion in IVS-2 have no effect. Oxygen equilibrium curves of the Hb A2 variants expressed in yeast were similar to that of wild type Hb A2. None of the three variant Hb A2 tetramers (Thr --> Ile at codon 4 (Hb deltaT4I), Ala --> Ser at codon 27 (Hb deltaA27S), and Arg --> Cys at codon 116 (Hb deltaR116C)) showed decreased heat stability compared with Hb A2, whereas the Hb deltaT4I variant showed highest instability to mechanical agitation. Co-expression in yeast of alpha-globin chain and the delta-chain variant containing a Leu --> Pro change at codon 141 yielded no identifiable tetramers, suggesting lack of assembly or severe tetramer instability. These studies show the probable cause for decreased Hb A2 for two alleles is due to defective splicing, whereas decreased protein stability, increased tetramer association with red cell membranes, increased interdisulfide bond formation of delta-chains, which inhibits assembly with alpha-chains, and/or reduced assembly is suggested for the other three alleles.     

Production of a TiN film with nanoscale particle size by a combined method of plasma-alloy reaction and spray deposition

On leave from: Honda Research and Development Co., Ltd, Wako 351-01, Japan.